The power folding top system includes a folding top cover that is powered open and close by a hydraulic system that is controlled by the FTC module. A power unlatch motor is used to unlatch the folding top cover before the folding top control (FTC) module powers the top cover open. The folding top cover unlatching is requested by the FTC module via class 2 message, but is executed by the body control module (BCM). When requested, the BCM applies battery voltage through the folding top cover release relay control circuit to the tonneau release relay. The relay is energized and battery voltage is applied through the folding top cover release control circuit to the latch actuator. The actuator is energized and the latch releases the folding top cover.

The purpose of the folding top cover pull down actuator is to compress the folding top when its in the down position while the cover is being closed.

Battery positive voltage is supplied at all times to the folding top cover pull down actuator from the TONNEAU RELEASE Fuse located in the BCM fuse block. The pull down actuator is also provided with a control circuit, an ajar status circuit, and a ground circuit.

After the folding top cover latch actuator releases the cover, an internal switch in the actuator opens the control circuit to the pull down actuator commanding it to raise the striker. The pull down actuator will turn itself off once the striker is fully extended. Then with the striker in the extended position, the folding top cover pull down ajar signal circuit is pulled low signaling the BCM the ajar status of the pull down actuator. After the folding top is in the desired position, and the folding top cover is closed and latched, the internal switch in the latch actuator closes pulling the control circuit of the pull down actuator to ground, commanding it to retract the striker. The pull down actuator then reverses polarity of its motor to retract the striker in order to finish closing the cover.

Schematic Reference

Folding Top Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Power Folding Top Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Important: This diagnostic test is to be used only in conjunction with other diagnostic procedures in this section. Using this diagnostic table without being directed to its use, may result in the misdiagnoses of the power folding top system. Refer to Power Folding Top Inoperative.

1. Ignition ON, verify the folding top cover pull down actuator is not continuously moving up and down.

⇒	If the pull down actuator continuously moves up and down, refer to the Folding Top Cover Pull Down Ajar Test.

2. If the folding top is in the open/stowed position, verify the scan tool Top Open Limit Switch parameter is Active.

⇒	If not the specified value, refer to the Top Open Switch Test.

3. If the folding top cover is in the closed and latched position, verify the scan tool Tonneau Latch Switch parameter is Closed.

⇒	If not the specified value, refer to the Folding Top Cover Latch Ajar Test.

4. During folding top operation when the sequence is reached for the folding top cover to open, the cover should unlatch.

⇒	If the cover did not unlatch, refer to the Folding Top Cover Latch Actuator and Relay Test.

5. After the folding top cover opens, the folding top cover pull down actuator should extend to the raised position.

⇒	If the pull down actuator did not extend to the raised position, refer to the Folding Top Cover Pull Down Actuator Test.

6. When the folding top cover reaches the closed position, the cover should latch.

⇒	If the cover did not latch, refer to the Folding Top Cover Pull Down Actuator Test.

7. Once the folding top cover is closed and latched, the folding top cover pull down actuator should retract to the down position.

⇒	If the pull down actuator did not retract, refer to the Folding Top Cover Pull Down Actuator Test.

Folding Top Cover Pull Down Ajar Test

1. Open the folding top cover. If needed use manual operation.
2. Ignition OFF, disconnect the harness connector at the folding top cover pull down actuator.
3. Test for less than 5 ohms between the ground circuit terminal D and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

4. Ignition ON, verify the scan tool Power Pull Down Ajar Status parameter is Closed.

⇒	If not the specified value, test the signal circuit terminal E for a short to ground. If the circuit tests normal, replace the BCM.

5. Install a 3A fused jumper wire between the signal circuit terminal E and the ground circuit terminal D. Verify the scan tool Power Pull Down Ajar Status parameter is Ajar.

⇒	If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

6. Verify that a test lamp does not illuminate between the control circuit terminal B and B+.

⇒	If the test lamp illuminates, test the control circuit for a short to ground.

7. If all circuits test normal, replace the folding top cover pull down actuator.

Top Open Switch Test

1. Ignition OFF, disconnect the harness connector at the top open switch.
2. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal B and ground.

⇒	If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance..

3. Verify the scan tool Top Open Limit Switch parameter is Inactive.

⇒	If not the specified value, test the signal circuit terminal A for a short to voltage. If the circuit tests normal, replace the FTC module.

4. Install a 3A fused jumper wire between the signal circuit terminal A and the ignition circuit terminal B. Verify the scan tool Top Open Limit Switch parameter is Active.

⇒	If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the FTC module.

5. If all circuits test normal, test or replace the top open switch.

Folding Top Cover Latch Ajar Switch Test

1. Ignition OFF, disconnect the X2 harness connector at the folding top cover latch actuator.
2. Test for less than 5 ohms between the ground circuit terminal B and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool Tonneau Latch Switch parameter is Closed.

⇒	If not the specified value, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the BCM.

4. Install a 3A fused jumper wire between the signal circuit terminal A and the ground circuit terminal B. Verify the scan tool Tonneau Latch Switch parameter is Ajar.

⇒	If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the folding top cover latch actuator.

Folding Top Cover Latch Actuator and Relay Test

1. Ignition OFF, disconnect the tonneau release relay.
2. Test for less than 5 ohms between the ground circuit terminal 86 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 87 and ground.

⇒	If the test lamp illuminates, test the control circuit for a short to voltage.

4. Verify that a test lamp illuminates between the B+ circuit terminal 30 and ground.

⇒

If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal 87 for a short to ground. If the circuit tests normal, test or replace the folding top cover latch actuator.

5. Connect a test lamp between the control circuit terminal 85 and ground.
6. Cycle the ignition OFF and ON in order to reset the BCM.
7. Ignition ON, command the Tonneau Relay ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒	If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

⇒	If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

8. Disconnect the X1 harness connector at the folding top cover latch actuator.
9. Test for less than 5 ohms between the ground circuit terminal 3 and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

10. Connect the X1 harness connector at the folding top cover latch actuator.
11. Connect a 3A fused jumper wire between the B+ circuit terminal 30 and the control circuit terminal 87. Verify the folding top cover latch actuator is activated.

⇒	If the folding top cover latch actuator does not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the folding top cover latch actuator.

12. If all circuits test normal, test or replace the tonneau release relay.

Folding Top Cover Pull Down Actuator Test

1. Ignition ON, disconnect the harness connector at the folding top cover pull down actuator.
2. Test for less than 5 ohms between the ground circuit terminal D and ground.

⇒	If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal A and ground.

⇒	If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test or replace the folding top cover pull down actuator.

4. Install a 3A fused jumper wire between the signal circuit terminal E and the ground circuit terminal D. Verify the scan tool Power Pull Down Ajar Status parameter is Ajar.

⇒	If not the specified value, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the BCM.

5. Ignition OFF, connect the harness connector at the folding top cover pull down actuator. Disconnect the X2 harness connector at the folding top cover latch actuator.
6. Ignition ON, toggle a 3A jumper wire between the control circuit terminal C and ground. The pull down actuator should retract when the circuit is grounded and extend when the circuit is open.

⇒	If the pull down actuator does not extend and retract, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, test or replace the folding top cover pull down actuator.

7. If all circuits test normal, test or replace the folding top cover latch actuator.

Top Open Switch

1. Ignition OFF, disconnect the harness connector at the top open switch.
2. Test for infinite resistance between the signal terminal A and the B+ terminal B with the switch in the open position.

⇒	If not the specified value, replace the top open switch.

3. Test for less than 1 ohm between the signal terminal A and the B+ terminal B with the switch in the closed position.

⇒	If not the specified value, replace the top open switch.

Tonneau Release Relay

1. Ignition OFF, disconnect the tonneau release relay.
2. Test for 60-120 ohms between terminals 85 and 86.

⇒	If the resistance is not within the specified range, replace the relay.

3. Test for infinite resistance between the following terminals:

•

30 and 85

•

30 and 86

•

30 and 87

⇒	If not the specified value, replace the relay.

4. Install a 3A fused jumper wire between relay terminal 85 and B+. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohms between terminals 30 and 87.

⇒	If greater than the specified range, replace the relay.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.